2007 TTR-125 LE Mikuni 24mm flat slide carburator upgrade
Here are some photos, they are big, so please be patient.
The Mikuni flat slide carb has been used on two stroke dirt bikes
forever, and they work great. The stock carb sucks bad, so I set
out
address this issue. My TTR is a blast, I don't have any interest
in making all that much faster, I have an RM or DRZ for that. I
saw
that horrible BBR thing with the old 26mm Kiehen on it and said 'hell no' to that, and the price...
The BRAND NEW Mikuni cost around $105. I used a one inch piece of 2024 Aluminum, and about forty minutes on the lathe.
Total investment, around $110 and some time. I am going to need a
handful four main jets, 110 to 125 to get it right. I may need to
change the pilot jet as well. Figure another $20 for jets on the high side, and about another hour to jet.
I rode the bike for about 25 minutes. It runs great right off,
but has too big a main jet and starts to break up on top. The
carb comes
with a 130 main, so I am going to try a 120 and see how it goes.
My bike has a stock exhaust with the big end cap, and the airbox
mod.
I have a stock air filter cage as the cage seemed pretty open and not a
cause of restriction. One thing I did change and seemed to make a
very big difference was match the intake manifold to the cylinder head, it was not well matched from the factory.
At any time I can take this carb off, and put the stock carb back on in about 15 minutes.
At this time, the only issue outstanding is I am not happy with the
throttle cable/top of carb junction. I need to seal it better.
If anyone is interested in one (or more details), let me know. Drop me an email at tjackson@tjsconcepts.com
Enjoy the photos!
Carb of the bike, the manifold adapter is shown next to the cylinder
head
Intake side, with adapter
Air intake bell. Fits in stock boot without issue
Carb top where throttle cable comes in, boot up
Carb top, boot down
Another picture
Left side, idle screw, float bowl drain, and fuel line
